Typically, a vehicle may include a steering system to help an operator steer the vehicle on a ground surface. Conventionally known steering systems may include a pump for operatively supplying pressurized fluid to one or more steering actuators of the vehicle so that the steering actuators can perform the steering functionality with the help of one or more wheels associated with the vehicle.
Sometimes, it may be possible that the pump may fail to operate as intended or the pump may not work at all. During such time, it is required for a back-up emergency steering system to take control of the steering functionality of the vehicle. An example of one such system is disclosed in U.S. Pat. No. 4,574,904 (hereinafter referred to as “the '904 patent”). The '904 patent discloses an auxiliary hydraulic steering system for use in mobile vehicles. This auxiliary hydraulic steering system has an engine-driven pump that supplies hydraulic fluid under pressure to a steering control unit and an accumulator. The accumulator is charged with fluid under pressure from the pump through a charger/discharge valve and connects with a supply line to the steering control unit only when the charge/discharge valve shifts in response to a predetermined pressure in said supply line.
Although the configuration of the auxiliary hydraulic steering system from the '904 patent provides for an accumulator that is charged with fluid under pressure at a first instant in time for use during a subsequent period of time, the auxiliary hydraulic steering system of the '904 patent does not provide a means for continuously charging the accumulator with the pressurized fluid from the pump during operation of the steering control unit so that at the same or a later instant of time, for instance, if the load on the steering actuators increases, the accumulator can simultaneously co-operate with the pump in actuating movement of the steering control unit and help reduce an amount of load on the pump.
Hence, there is a need for an improved hydraulic steering system that is simple in construction yet effective in overcoming the aforementioned drawbacks.